Large Area Platinum and Fluorine-doped Tin Oxide-free Dye sensitized Solar Cells with Silver-Nanoplate Embedded Poly(3,4-Ethylenedioxythiophene) Counter Electrode

Abstract

Low-temperature, cheap, highly conductive triangular silver-nanoplates (Ag-NPs) embedded in poly (3, 4-ethylenedioxythiophene) (PEDOT) films were prepared on bare glass substrates via spin coating and chemical polymerization. The films acted as a very good alternative to conventional platinum (Pt) and fluorine-doped tin oxide (FTO) counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The effect of the Ag-NPs in the PEDOT CE was evaluated by adding different weight ratios of Ag-NPs (0.06, 0.60, and 1.20wt%) to the PEDOT solution before producing the film, and the catalytic and conductive properties were compared against those of pristine PEDOT films for use in DSSCs. The catalytic properties of all CEs in the DSSCs were characterized via cyclic voltammetry (CV), current-voltage (I-V) measurements, and electrochemical impedance spectroscopy (EIS). The PEDOT CE with embedded Ag-NPs functioned as excellent electrocatalysts for tri-iodide reduction, as compared to pristine PEDOT CEs. DSSCs (cell area: 1cm2) with the 0.60wt% samples exhibited a power conversion efficiency of 6.0% under 1 sun illumination (100mWcm−2), which is higher than that of DSSCs with pristine PEDOT CE (5.5%). The Ag-NPs embedded PEDOT CE has very good catalytic activity and conductivity, which is more suitable for large area Pt and FTO less DSSC. In addition, no noticeable efficiency decay was observed after adding Ag-NPs in PEDOT CEs.